Move more sources from modules.gypi to subdirectories.

third_party/WebKit/Source/modules/encoding/BUILD.gn

Index: third_party/WebKit/Source/modules/encoding/BUILD.gn
diff --git a/third_party/WebKit/Source/modules/srcobject/BUILD.gn b/third_party/WebKit/Source/modules/encoding/BUILD.gn
similarity index 59%
copy from third_party/WebKit/Source/modules/srcobject/BUILD.gn
copy to third_party/WebKit/Source/modules/encoding/BUILD.gn
index f97e4b0d66d01539e7937b035892a645a9b1020c..842636f2ef675e1abe96bdc2c696f9be74d2c774 100644
--- a/third_party/WebKit/Source/modules/srcobject/BUILD.gn
+++ b/third_party/WebKit/Source/modules/encoding/BUILD.gn
@@ -4,9 +4,13 @@
 
 import("//third_party/WebKit/Source/modules/modules.gni")
 
-blink_modules_sources("srcobject") {
+blink_modules_sources("encoding") {
   sources = [
-    "HTMLMediaElementSrcObject.cpp",
-    "HTMLMediaElementSrcObject.h",
+    "Encoding.cpp",
+    "Encoding.h",
+    "TextDecoder.cpp",
+    "TextDecoder.h",
+    "TextEncoder.cpp",
+    "TextEncoder.h",
   ]
 }